The newest, say, the usual 40 years’ old glass range I have. When you need a lot of light, you go for a normal f1.4 lens. This time my choice is the Auto Chinon 55mm f1.4 M42 mount that I use on my DSLR with a M42 to K mount adapter. The lens feels very solid, something I adore about the old lenses, at the same time feels more compact than the Revuenon 55mm 1.4 I used to have. Rumours have it Chinon produced lenses for Carl Zeiss Jenna (CZJ) in Eastern Germany. Or were made by Tomioka, yet I’d attribute those to photographers’ obsession with hardware and ability to produce urban legends. And still, the glass appears very well made, with a very long focus throw which I love: something like 270 degrees of a turn. The other thing I love about it, is the aperture clicks: the usual f1.4 lenses do not have extra stops between f1.4 and f.2, an example of this would be the Pentax SMC 50mm f1.4, or the Auto Revuenon 50mm f1.4 that immediately jump to f2 and thus make the large aperture almost useless, due to sharpness issues. This one is very good wide open, until one can nail the focus down due to depth of field issues. Which at the same time is one of the most fascinating things about wide open lenses. I feel f1.4 is the limit, f1.2 would be practically useless from that point of view.
The lenses exhibit a sort of a flare, which I can understand, after all, Pentax were the ones to come up with the SMC coating as a remedy, so I can’t really complain. The defect I feel is using it with the adapter: infinity focus sometimes is blurred, therefore I’d advise that you use a Pentax M42 to K mount adapter, and not a cheap Chinese one, as me. Ideal as the 55 x 1.5 crop provide a very good length (say, 82mm on a 35mm frame), I’d really use it for portraits, objects [about 50cm of minimal focus distance to object], street photography, low light settings, but for landscapes I’d not. My copy has slight fungus inside and very minor scratches, but given the fact that I usually shoot very wide open, they’d hardly affect the photo.
All photos have been taken by f1.4, ISO 100 on a Pentax K20D.